The disk storage apparatus plays an important role as external storage apparatus for storing data and programs in a data processing system such as a personal computer. Disk storage apparatus are divided into two types: One type is a floppy disk storage apparatus or an optical or magneto-optical storage apparatus in which the mediums are exchangeable. The other type is a fixed magnetic hard disk storage apparatus in which the medium is unexchangeable. The fixed magnetic hard disk storage apparatus has a fast rotatable disk medium and a fast movable head actuator in an enclosure of which environment is controlled. Therefore, it has a large amount of storage and is provided with fast access and the high performance of reading and writing operations by using an electromechanical servomechanism of high precision. Therefore, in this respect, it is superior to a disk storage apparatus in which the medium is exchangeable. However, such a fixed magnetic hard disk storage apparatus could not be freely exchanged and carried around until recently, because it is relatively large-sized and has a mechanical structure of high precision which is very vulnerable to shock.
Currently, however, the so-called 2.5-inch type of fixed magnetic hard disk storage, which is about 10 cm.times.7 cm.times.1.3 cm in size, about a hundred and several tens grams in weight, and has a storage capacity of more than 40M bytes, is on the market, A 1.8-inch type of fixed magnetic hard disk storage unit has also appeared which is smaller and lighter than the 2.5-inch type and the storage capacity and access time of which are much the same as the 2.5-inch type. Under such circumstances, the fixed magnetic disk storage apparatus has now become exchangeable and portable.
On the other hand, as the performance and functions of hardware and software of a personal computer, which is a body of a data processing system, improve, for example, the appearance of a portable notebook-type personal computer, the necessity of storing a large amount of data and programs at high speed and the demand for a fixed magnetic disk storage apparatus which is small-sized, light, exchangeable, and portable increase by degrees.
Prior art references, Japanese Published Unexamined Patent Applications (PUPAs) No. 3-137882, No. 1-319194, and No. 62-137761 disclose conventional types of exchangeable and portable fixed magnetic hard disk storage apparatus. Japanese PUPA No. 3-137882 discloses an exchangeable and portable fixed magnetic hard disk storage apparatus, in which a head/disk enclosure is elastically supported on a frame body by using a vibration-proof rubber damper and an electronic card attached to the head/disk enclosure is connected, through a flexible cable, to a connector. It also discloses a construction in which the head/disk enclosure and the electronic card are detached and arranged so as to be overlaid with each other in the frame body and only the head/disk enclosure is elastically supported on the frame body by using the vibration-proof rubber damper. Japanese PUPAs No. 1-319194 and No. 62-137761 disclose a construction in which a disk drive body is elastically attached to a case and electrically connected to the outside through a flexible cable.
Since a disk storage apparatus includes a mechanical construction of a rotatable disk and a head actuator moving on the disk, such a mechanical construction may be damaged by shock. Therefore, for a portable disk storage apparatus, measures must be taken to absorb shock. Though measures to absorb shock are taken in the portable disk storage apparatus disclosed in the above Japanese PUPAs of prior art, there are still some problems to be solved in respect to absorbing shock as well as to making the portable disk storage apparatus small and thin and making its manufacturing and assembling process simple, which are other important factors for the portable disk storage apparatus.